The present invention relates to a vehicle front brake, and more specifically to a swivel adjustment member for a vehicle front brake for adjusting the pitch between the brake arms of the vehicle front brake, which is durable and practical in use.
FIGS. from 1 through 3 show a vehicle front brake according to the prior art. This structure of vehicle front brake comprises a swivel adjustment member 4 turned about a shaft relative to a cable guide 43 between two positions to adjust the pitch between the brake shoes 441 and 451 at two brake arms 44 and 45. The swivel adjustment member 4 comprises two parallel sidewalls 41, a connecting wall 42 connected wall 42. The sidewalls 41 each have a short side 411 and long side 412 connected at right angles and alternatively forced into engagement with positioning grooves 431 of the cable guide 43. This structure of swivel adjustment member 4 is not satisfactory in function, and has numerous drawbacks as outlined hereinafter.
1. Because the connecting wall 42 is a narrow wall transversely connected between the sidewalls 41 remote front the short side 411 of each sidewall 41, the sidewalls 41 tend to be forced outwards and deformed, causing a positioning failure in the positioning grooves 431 of the cable guide 43. PA1 2. Because the short side 411 defines with the longitudinal central line of the respective sidewall 41 a 90 .degree. contained angle, the sidewalls 41 tend to be forced away from the positioning grooves 431 of the cable guide 43 by an external force. PA1 3. Because the handle 421 extends from the connecting wall 42 in direction reversed to the long side 412 of each sidewall 41, the handle 421 may hinder the operation of the brake arms 44 and 45 when the short side 411 of each sidewall is respectively engaged into the positioning groove 431 of the cable guide 43. PA1 4. Because the short side 411 defines with the longitudinal central line of the respective sidewall 41 a 90 .degree. contained angle, it takes much effort to shift the swivel adjustment member 4 between the two positions.
The present invention has been accomplished to provide a swivel adjustment member for a vehicle front brake, which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the swivel adjustment member comprises two parallel sidewalls, a connecting back wall connected between the sidewalls, and a handle extended from the back connecting wall, wherein the connecting back wall of the swivel adjustment member has a top side connected between the short top side of each sidewall to reinforce the structural strength of the swivel adjustment member, and to prevent the sidewalls from being stretched outwards or deformed when forced into engagement with the positioning grooves of the cable guide. According to another aspect of the present invention, the sidewalls each have a short top side and a long front side alternatively forced into engagement with the positioning grooves of the cable guide, and the handle is extended upwardly backwards from the top side of the connecting back wall adjacent to the short top side of each sidewall. After positioning of the swivel adjustment member in either of the two positions, the handle does not hinder the operation of the brake arms. According to another aspect of the present invention, the short top side of each sidewall of the swivel adjustment member has a straight engagement portion obliquely backwardly sloping toward the connecting back wall and the handle, and a parabolic guide portion connected between the straight engagement portion and one end of the long front side of the corresponding sidewall. The parabolic guide portion enables the sidewalls to be smoothly shifted between the two positions. According to still another aspect of the present invention, the contained angle defined between the straight engagement portion and the longitudinal central line of the corresponding sidewall is smaller than 90 .degree., so that the short top side of each sidewall can be positively respectively positioned in the positioning grooves of the cable guide. According to still another aspect of the present invention, the handle has a fixed and connected to the topside of the connecting back and one end of the straight engagement portion of the short topside of each sidewall. After the short topside of each sidewall of the swivel adjustment member has been respectively forced into engagement with the positioning grooves of the cable guide, the handle is stopped at the periphery of the cable guide to hold the swivel adjustment member in place.